A tsunami warning system in south-west Aegean Sea, Greece

Gerassimos A. Papadopoulos
Institute of Geodynamics, National Observatory of Athens, P.O. Box 20048 11810 Athens, Greece.
Tel. : +301-3462664, Fax: +301-3426005

One of the most tsunamigenic regions of Europe is the Kythira Strait between Peloponnesus and Crete Island. Large, destructive tsunamis have been reported there in historical times such as the waves of 66 A.D., 365, 1630 and 1866, all of them being associated with respective large earthquakes. Future tsunamis to be generated in that area could cause near-field as well as far-field effects. Since the tsunami travel times are locally very short, near-field effects are expected within only about 10 min from the tsunami origin time. Therefore, the Greek research team that is participating in GITEC-TWO has selected the Kythira Strait, SW Aegean Sea, for the development of a local tsunami warning system (TWS). Before establishing such a TWS its operational efficiency should be firstly tested by considering its response capability. The main purpose of the test is to evaluate the maximum alert time, that is the time interval between the origin time of a potentially tsunamigenic strong earthquake and the maximum acceptable time for setting up a tsunami alert. To this goal an experimental system for monitoring the earthquake activity and the sea level changes has been developed. The system consists of a number of digital seismographs and tide-gauges. A 24-hour operation of the system and an on-line data transmission and automatic elaboration at the Institute of Geodynamics, Athens, has been scheduled.